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thadman
12-15-2005, 12:02 AM
Im considering building a small budget HT setup for my computer/xbox 360 and have decided on efficient fullrange drivers. They are 97dB @ 1w/1m (extremely good efficiency) and have an RMS of around ~30 watts. Would it be possible to build amps for these speakers and run them off of an M-Audio Revolution 5.1 sound card?

~15 watts per channel would be all I would even begin to use (I doubt, but may use 30 watts)

How hard would it be to build amplifiers for these drivers?

thadman
12-15-2005, 12:05 AM
If not, what would be a nice reciever that I could get for $100-150 shipped on ebay that has at least ~20 watts of clean power to each channel.

Beat_Dominator
12-15-2005, 12:12 AM
Well the idae is fun, but for the cost and labor you'd have to put into it... not to mention the circuitry to make it a multi-channel setup really wouldn't be worth it. Just find yourself a name brand reciever on ebay that has all of the dolby digital decoding and use an optical out of the sound card.

thadman
12-15-2005, 12:15 AM
I couldnt do 5 individual ~20 watt amps?

Maybe im thinking outloud

thylantyr
12-15-2005, 01:39 PM
There are DIY solutions for 20w amps, the question now becomes 'skill' to
execute the design. Can you build an amplifier using chipamps? That is
the most basic amplifier design you can do and it easily meets your power requirement.

JimJ
12-15-2005, 05:22 PM
Chip amps :(

A single-ended design using MOSFETs would be cool, something along the lines of Nelson Pass's Zen amplifier.

http://www.passdiy.com

stones
12-15-2005, 05:38 PM
The Source (radio shack) still sells small 40 watt PA amp for under $100.
link-
http://www.radioshack.com/product/index.jsp?productId=2103829&cp=&kw=pa+amplifier&parentPage=search

thylantyr
12-15-2005, 06:53 PM
Check this out.

Jeff Rowland Model 10 amplifier;
http://www.jeffrowland.com/img/M10-front.jpg
http://www.jeffrowland.com/img/M10-back.jpg

Pretty.

Specs;
http://www.jeffrowland.com/ClassicSpecs.htm#M10

Suggested Retail Price:, $7500




... Lets peak inside ...

http://www.shine7.com/audio/jeff.htm

A bunch of LM3886T chip amps.... bwahahahahahahahahahahaha..

:laugh: :laugh: :laugh: :evil:

JimJ
12-15-2005, 08:52 PM
Check this out.

Jeff Rowland Model 10 amplifier;
http://www.jeffrowland.com/img/M10-front.jpg
http://www.jeffrowland.com/img/M10-back.jpg

Pretty.

Specs;
http://www.jeffrowland.com/ClassicSpecs.htm#M10

Suggested Retail Price:, $7500




... Lets peak inside ...

http://www.shine7.com/audio/jeff.htm

A bunch of LM3886T chip amps.... bwahahahahahahahahahahaha..

:laugh: :laugh: :laugh: :evil:

:hilariou:

That's funny.

Audiophool pwnage.

thylantyr
12-16-2005, 01:43 AM
:hilariou:

That's funny.

Audiophool pwnage.

More funnay... that product is listed in their 'Classic Products' section
showing that amp date from 1999 - 2004 ... so for 5 years they were
able to fool people...... and now they use ICEpower [class D] in their new
Concerto integrated.

Jeff Rowland is an interesting company being bold to try things out of the box
in the audiophile world, ie using switch mode powersupply, using chipamps,
and now using ICEpower. I think they also use digital volume and line level
transformers, more 'stuff' in the audio path that goes against audiophile thinking.

thylantyr
12-16-2005, 01:29 PM
Some folks are buying the sonic-T amp for cheap {~$30) and gutting it and making
their own chassis. You could place a bunch of sonic-T's inside one chassis
to make a multi-channel amp.

http://www.tnt-audio.com/ampli/t-amp_opinions_e.html

http://www.diyaudio.com/forums/showthread.php?s=&threadid=41846

thch
12-16-2005, 04:24 PM
Chip amps :(

A single-ended design using MOSFETs would be cool, something along the lines of Nelson Pass's Zen amplifier.

http://www.passdiy.com

or just use an lm1875. 5 pins and your done. make sure to get a heatsink. note that the tabs are connected to the negative supply voltage.

zen looks like a transconducatance amplifier with multiple current feedback paths. it seems R3 and R5 do the same thing.

req
12-16-2005, 04:31 PM
this is prolly the absolutle best budget amp for that power range you can buy

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=300-952

i have one and its freaking awesome.

YOU WILL NEED ONE OF THESE!!! (lol, i happened to have a printer that had a 1.2 amp 15v transformer that was laying around :D )
http://www.allelectronics.com/matrix/DC_Wall_Transformers.html

13.5 Vdc 1 amp 2.1mm co-ax positive C DCTX-1351 $5.50

for under $45 for everything, you cant really beat it. mine sounds awesome.

thch
12-20-2005, 10:39 PM
i disagree. he would need 3 of these $30 modules and 3 transformers for this to work.

i propose getting the required parts for a lm1875 amp from apexjr.com and then ordering samples of the IC at www.national.com

i am in a text browser, so i won't post links.

apex should have an $8 24Vct 7A (48V with 220V inputs) transformer.
2 10,000uF or so caps, 50V rated, for $1. get 2 extra in case you mess up.
fused IEC power connection box and line filter $3
full wave rectifier, 25A, $3.
speaker terminals, 2x6, $2.
input RCA jacks (i don't know this one).
Heatsink $4.
find some resistors and bipolar caps and wire and you have all thats needed. with a dremel you should be able to use PCBs from radioshack.

PowerNaudio
12-25-2005, 12:01 PM
i disagree. he would need 3 of these $30 modules and 3 transformers for this to work.

i propose getting the required parts for a lm1875 amp from apexjr.com and then ordering samples of the IC at www.national.com

i am in a text browser, so i won't post links.

apex should have an $8 24Vct 7A (48V with 220V inputs) transformer.
2 10,000uF or so caps, 50V rated, for $1. get 2 extra in case you mess up.
fused IEC power connection box and line filter $3
full wave rectifier, 25A, $3.
speaker terminals, 2x6, $2.
input RCA jacks (i don't know this one).
Heatsink $4.
find some resistors and bipolar caps and wire and you have all thats needed. with a dremel you should be able to use PCBs from radioshack.


i agree, for an easy, low budget amp, with decent power rating for home audio. use the chip amps. making a class a, or an ab amp will requier more parts, and cost more, and you have to have some experiance to build.
as for a chip amp aslong as you can read an electronic schematics you can build one in a couple of hours.

and you can get them in 1, 2, 3, 4, channels and more. and all youll need to do is add some components, to make the chip amp fuctional. also you can build the powersupply powerfull enogh so if in the future you decide to replace the chip amps with some more power full ones like the LM12 the you wont need to change the power supply.
any ways here is a link full of great info if you acctualy interested in building amps.
you may have seen it all ready but here you go.

http://sound.westhost.com/projects.htm
http://www.firstwatt.com/
http://www.diyaudio.com/
http://www.passdiy.com/default.htm

those are just a couple of them, use google it will find a **** loads of info on this subject.

dont_smokerocks
12-26-2005, 01:32 AM
heres a sweet little amp.
http://www.allelectronics.com/cgi-bin/category.cgi?category=937&item=AMP-30&type=store

15 x 2 for 20 bucks